@misc{indiciaeb9a8eabf6cec,
  title = {Altitude and configuration of the potentiometric surface in Upper Elk Creek watershed, Chester County, Pennsylvania, January through June 1999},
  author = {Abdul Mohammad},
  year = {2000},
  doi = {10.3133/ofr99475},
  url = {https://pubs.usgs.gov/publication/ofr99475},
  note = {Source identifier: ofr99475}
}